What are the key aspects of preparing for and presenting oneself in a job interview, including resume writing?

Here are the answers to the questions:

20. Listening skill is important in:
(3) Both (1) and (2)
Listening skills are essential in both interviews to understand questions and in group discussions to follow the conversation and contribute effectively.
The correct option is $\boxed{\text{(3)}}$.

21. रिज़्यूम क्या है? (What is a resume?)
(2) योग्यता का सार (Summary of qualification)
A resume is a document that provides a summary of your qualifications, skills, and experience for potential employers.
The correct option is $\boxed{\text{(2)}}$.

22. रिज़्यूम कैसा होना चाहिए? (How should a resume be?)
(2) स्पष्ट और संक्षिप्त (Clear and Concise)
A resume should be clear and concise, presenting relevant information in an easy-to-read format.
The correct option is $\boxed{\text{(2)}}$.

23. साक्षात्कार की तैयारी में क्या शामिल है? (What is included in interview preparation?)
(4) उपरोक्त सभी (All of the above)
Interview preparation includes gaining knowledge about the company, practicing questions, and ensuring proper dressing. All these aspects are crucial for a successful interview.
The correct option is $\boxed{\text{(4)}}$.